1. Field of the Invention
The invention is generally directed to a system for supplying a superheated hydrocarbon or hydrocarbon/water mixture to at least two components of a gas generation system of a fuel cell system, in particular to at least two stages of a multi-stage reforming process.
2. Description of the Related Art
Generation systems for producing hydrogen-containing gases for use in fuel cell systems, in particular for use in mobile applications such as motor vehicles, comprise several components. In addition to the components that are usually connected in series, such as a reformer, a purification stage or similar elements, the operating state of the fuel cell system may make it necessary to supply an evaporated and/or superheated hydrocarbon or hydrocarbon/water mixture to at least two components of the gas generation system in parallel. For this purpose, two separate systems to evaporate or superheat the hydrocarbon or the hydrocarbon/water mixture are typically employed.
For example, DE 196 39 150 C2 describes a system that provides the thermal energy needed for the evaporation and/or superheating of the hydrocarbon or hydrocarbon/water mixture by means of a central heating device. A fuel and an oxygen-containing gas are catalytically oxidized in the central heating device and the thermal energy generated is then supplied to the individual system components of the gas generation system by means of a heat transfer medium. This distribution of thermal energy requires appropriate pipe elements, which connect the heat-transfer medium side of the central heating device with the individual system components. However, these transfer areas and pipe elements are subject to significant heat losses, which lower the overall efficiency of the system.
Another disadvantage of a system that uses a heat transfer medium to distribute generated thermal energy, is that is does not possess the dynamic response characteristics required for mobile applications, such as motor vehicles. A further disadvantage of such a system is that the heat transfer medium and the components that are to be supplied must be heated to an appropriate operating temperature by the central heating device before the entire system is able to provide gas generation operations proportionate with the load requirements put on a fuel cell of the fuel cell system.
Accordingly there remains a need for a system for supplying a superheated hydrocarbon or hydrocarbon/water mixture to components of a gas generation system that overcomes the disadvantages associated with a system that uses a heat transfer medium to distribute the generated thermal energy. The present invention fulfills one or more of these needs, and provides further related advantages.